Fluid flow control for gas burner



1957 P. L. F. FEYLING FLUID mow CONTROL FOR GAS BURNER Filed May 22, 1953 United States Patent FLUID FLOW CONTROL FOR GAS BURNER Per L. F. Feyling, Belmont, Mass.,'assignor to J. W. Greer Company, Wilmington, Mass., a corporation of Massachusetts Application May 22, 1953,'Serial No. 356,787

2 Claims. (Cl. 158-114) This invention relates to fluid flow control and pertains more specifically to an adjustable elongated gas burner having means for continuously varying the volume of gas delivered along the length of the burner.

Elongated gas burners are widely employed for heating continuous metal belts employed in baking pastry and the like on a commercial basis. The burners ordinarily are mounted transversely of the metal conveyor belt, the number of burners employed being dependent upon the length of the belt, its speed of travel, etc. In order to achieve uniform heating of the belt across its width and thus obtain uniform baking of the pastry or the like disposed on the upper surface of the belt, it is essential that the height of the flame be subject to control from point to point across the width of the belt. Although there have previously been made proposals for controlling the volume of gas delivered, and hence varying the height of the flame at each point along the length of such elongated gas burners, such devices have been expensive and complicated in structure and have failed to provide the necessary flexibility of control.

One object of the present invention is to provide an elongated gas burner suitable for use in a continuous baking oven together with mean for varying the height of the flame from point to point along the length of the burner.

Another object is to provide a fluid-flow control device of simple and inexpensive construction which does not require careful maintenance.

Still a further object is to provide a transversely flexible damper extending along the length of an elongated gas burner transversely of the direction of gas flow and having means for adjustably rotating each end of the damper independently of the other so as to vary continuously the volume of gas delivered from one end of the burner to the other.

Other and further objects will be apparent from the description which follows.

One embodiment of my invention is shown in the appended drawings =in which Fig. 1 is a view in longitudinal section of a gas burner constructed in accordance with the present invention;

Fig. 2 is a view in section taken along line 2-2 of Fig. 1;

Fig. 3 is a view similar to Fig. 2 showing the damper in a dilferent position; and

Figs. 4 to 7 inclusive are schematic views showing several dilferent possible positions of the flexible damper together with the shape of the flame which results therefrom.

The gas burner as shown in Fig. 1 includes a distributing pipe 10 extending along the length of the burner and provided with an inspirator pipe 11 at one end. The gas inspirator pipe is provided with a conventional gas inlet 12, air shutter 13 and orifice spud 14. The opposite end of distributor pipe 10 likewise is provided with a tapped opening into which a length of pipe 15 is threaded, this pipe being provided with a cap 16.

Inspirator pipe 11 and capped pipe 15 may conveniently be employed for supporting the burner in the desired position.

Distributor pipe 10 is provided with an elongated outlet channel 20 extending laterally from distributor pipe 10 substantially along its length and with reinforcing ribs 29 extending across outlet channel 20 at spaced intervals. Outlet channel 20 terminates in a plurality of small burner orifices which may be provided by an assembly 21 of crimped metal ribbons or tapes disposed in the outer end of the outlet channel, as is well known in the art.

Mounted within outlet channel 20 inwardly of burner orifices 21 and extending along the length thereof is a transversely flexible thin metal ribbon or tape 22, each end of which is secured to pins 23, 24 rotatably mounted in apertures in the end walls of outlet channel 20 and secured in place with lock nuts 25, 26. In order to provide for ease in rotating, the pin may be provided with a slotted end as at 27 which will receive a screwdriver, or the head of the stud may be provided with a handle 28.

In operation the metallic tape or ribbon 22 acts as a damper. When disposed in the position shown in Figs. 1 and 2 it permits substantially unobstructed flow of the mixture of combustible gas and air from the distributor pipe 10 through burner orifices 21 resulting in a flame 30 of substantially uniform height along the length of the burner. By twisting one end of ribbon damper 22 through until it attains the closed position shown in Figs. 3 and 4, the flow of gas at one end of the burner is greatly reduced, resulting in a flame 31 of gradually decreasing height from one end of the burner to the other.

:Figs. 5 and 7 show graphically other shapes of flame which may be achieved by twisting one or both ends of the ribbon damper to the positions indicated. 'In Fig. 5, the central portion of the ribbon damper is in the closed position and both ends are in the open position, resulting in a flame of minimum height near the center of the burner and increasing gradually to maximum height at both ends. Fig. 6 shows the damper closed at the end opposite that of Fig. 4, while Fig. 7 shows the damper open at the center and closed at both ends with a twist.

It will be readily apparent that the present invention makes possible very close control of flame height along the length of a gas burner so that the amount of heat supplied at any point along the burner may be adjusted at will.

It will also be readily apparent that the ribbon damper of the present invention may be applied to air ducts or other channels for delivery of fluid in order to vary the volume of fluid flow across the duct or channel. It has been found that a thin flexible stainless steel tape or ribbon is eminently suitable for use as the damper, but it will be apparent that numerous other tapes or ribbons made of metallic or non-metallic material may be employed provided that they possess transverse flexibility so as to enable the ribbon to be twisted along its length by adjustably rotating one end of the ribbon independently of the other.

Although I have herein described a specific embodiment of my invention, I do not intend to limit myself solely thereto, but to include all of the obvious variations and modifications within the spirit and scope of the appended claims.

I claim:

1. A gas burner having an elongated chamber, means for introducing gas at an end thereof, said chamber having an elongated slot orifice leading therefrom and means for selectively varying the intensity of the flame emanating from said orifice substantially throughout the Patented .Feb. 19, 1957,

length thereof, said means comprising a transversely flexible, longitudinally twistable, thin, elongated damper twistable to at least 90 along its longitudinal axis mounted within said orifice and having its longitudinalaxis extending parallel to the length. of said orifice, and means for independently rotating each end of the damper about the longitudinal axis thereof to twist said damper about its longitudinal axis "at least 90 so that 'at least a portion of a face of said damper is at least 90 out of phase with another portion of said face for obstruct ing said orifice to varying extents along its length.

2. The method of selectively controlling fluid flow of combustible gases through a gas burner having an elongated chamber wherein gas enters the chamber from an end thereof and. emanates from a slot of relatively long and narrow cross-sectional configuration in one side of said chamber to selectively vary the intensity of the flame emanating from the slot which comprises rotating one end at least 90 independently of the other end of a thin, relatively long and narrow, transversely flexible and longitudinally twistable damper positioned within the slot and positioned with its longitudinal axis extending parallel to the length of the slot in the long cross-sectional direction so that at least a portion of a face of the damper is at least 90 out of phase with another portion of the face to selectively obstruct the slot to varying extents along the length thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,407,098 Stichler Feb. 21, 1922 2,044,953 Palmer June 23, 1936 2,068,567 Palmer Jan. 19, 1937 2,652,107 Hughes Sept. 15, 1953 FOREIGN PATENTS 22,991 Great Britain of 1904 

